From 685d84a7862eb0ca80e47f4179a7f0774462e539 Mon Sep 17 00:00:00 2001 From: Jonathan Zhou Date: Wed, 16 Sep 2020 13:17:36 -0600 Subject: [PATCH] coresight: etm4x: Fix mis-usage of nr_resource in sysfs interface The member @nr_resource represents how many resource selector pairs, and the pair 0 is always implemented and reserved. So let's multiply by 2 when resetting the selector configuration. And also update the validation of the input @idx. Cc: Mathieu Poirier Cc: Suzuki K Poulose Cc: Mike Leach Cc: Shaokun Zhang Signed-off-by: Jonathan Zhou [Fixed typographical error in changelog, added stable] Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20200916191737.4001561-16-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index a588cd6de01c..989ce7b8ade7 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -236,7 +236,7 @@ static ssize_t reset_store(struct device *dev, } config->res_idx = 0x0; - for (i = 0; i < drvdata->nr_resource; i++) + for (i = 2; i < 2 * drvdata->nr_resource; i++) config->res_ctrl[i] = 0x0; config->ss_idx = 0x0; @@ -1663,8 +1663,11 @@ static ssize_t res_idx_store(struct device *dev, if (kstrtoul(buf, 16, &val)) return -EINVAL; - /* Resource selector pair 0 is always implemented and reserved */ - if ((val == 0) || (val >= drvdata->nr_resource)) + /* + * Resource selector pair 0 is always implemented and reserved, + * namely an idx with 0 and 1 is illegal. + */ + if ((val < 2) || (val >= 2 * drvdata->nr_resource)) return -EINVAL; /*